Measure Countertop Runs, Islands, Backsplashes and Slab Needs
Add up to four rectangular runs, include an island and backsplash, subtract cutouts, apply fabrication waste and estimate full slab count.
SQ FT
Countertop measurements
Countertop quantity
How the countertop square footage calculator works
Each countertop run is length multiplied by finished depth, divided by 144 to convert square inches to square feet. The island and backsplash are calculated separately so a full-height splash is not confused with standard countertop depth.
Cutouts, waste and slabs
Sink and cooktop cutouts are subtracted from the net installed area. Fabrication waste is then added because veining direction, edge damage, seams and shape nesting can require more stone than the finished square footage. Slab count rounds the waste-adjusted area up to whole usable slabs.
Should I subtract the sink cutout?
Use the subtraction for material area planning, but many fabricators still price the cutout labor and may charge for the entire slab containing it.
What depth should I enter?
Measure the finished front-to-back depth, including the cabinet overhang. A common U.S. base-cabinet top is about 25 to 25.5 inches, but field measurements control.
Measure each run along the wall and use the finished depth. Handle backsplashes, islands and cutouts separately so the fabricator can apply its own slab layout, seam, minimum-charge and sink-cutout policies.